The Biopsychosocial Model and Case Formulation (also known as the Biopsychosocial Formulation) in psychiatry is a way of understanding a patient as more than a diagnostic label. Hypotheses are generated about the origins and causes of a patient's symptoms. The most common and clinically practical way to formulate is through the biopsychosocial approach, first described in 1980 by George Engel.[1][2] Biopsychosocial formulation combines biological, psychological, and social factors to understand a patient, and uses this to guide both treatment and prognosis. Your formulation of a patient evolves and changes as you collect more information. Formulation is like cooking, and there is no 'right' or 'wrong' way to do it, but most get better over time with increasing clinical experience.
Diagnosis is not the same as formulation! In mental health, when there is a group of consistent symptoms seen in a population, these symptoms can be categorized into a distinct entity, called a diagnosis (this is what the DSM-5 does). For example, we diagnose someone with a major depressive episode if they meet 5 of the 9 symptomatic criteria. However, formulation tells us how the person became depressed as a result of their genetics, personality, psychological factors, biological factors, social circumstances (childhood adverse events and social determinants of health), and their environment.
You are probably already formulating, but just don't know it. Like most things in medicine, there are multifactorial causes of diseases, illnesses, and disorders. For example, type II diabetes does not develop because of a single pathophysiological cause. The patient may have a strong family history of the disease, a sedentary job, environmental exposures, and/or a nutritionally-poor diet. These factors all combine to cause the person to develop diabetes. Understanding how each factor contributes to a disease can better guide treatment decisions. In psychiatry, formulation appears more complicated because human behaviour and the brain itself is extraordinarily complex. However, like with anything, the more you practice, the better you will become at formulating.
The biopsychosocial model considers the “4 Ps” for each of the biological, psychological, and social factors:
The “4 Ps” can be laid out in a 3 x 4 table to systematically do formulation and identity factors. Note that this table is extremely comprehensive and long, and not everything will (or should!) apply to your case. It is important to remember that not everything will fit neatly into each box. For example, many precipitating and perpetuating factors may overlap and fit in other boxes. Use this table as a general guide, but don't memorize it for the sake of memorizing it!
Biological | Psychological | Social | |
---|---|---|---|
Predisposing (What is their “set up?” What were they working with initially?) | • What was their temperament at birth? • What do we know about their consistent personality characteristics? • Is there a family psychiatric history? • Are there toxic exposures in utero, birth complications, or developmental disorders? • Is there a history of concussions or traumatic brain injuries? • Neurodevelopmental history | • What is their attachment style? • How did their family act and what is the family structure (i.e. - did the patient model their parent's behaviours, or did they rebel against their parent's behaviours – you either “act like your parents” or “act the opposite of your parents because you don't want to be like them”)? • Do they have problems with affect modulation? • Do they have a rigid or negative cognitive style? • Low self-image/self-esteem? | • Poverty, low socioeconomic status, teenage parenthood, or poor access to health care? • Childhood exposure to maternal depression, domestic violence, late adoption, temperament mismatch, or marital conflicts? • Immigration history, marginalization, discrimination, or racism? • Exposure to antisocial personality/traits |
Precipitating (What acute event happened and how did it affect them?) | • Serious medical illness or injury? • Increasing use of alcohol or drugs? • Medication non-adherence? • Pregnancy or hormonal changes? • Sleep deprivation? | Stressor that activate one or more psychological processes: • Cognitive: core beliefs and cognitive distortions • Dialectical: emotional dysregulation and dysfunction • Interpersonal: grief, loss, disagreement, change/transitions • Psychodynamic: unconscious conflicts/defenses, and unconscious repetition of early relationship patterns (psychic determinism) | • Loss of or separation from close family, partner, or friends • Interpersonal trauma • Work/academic/financial stressors • Recent immigration, loss of home, loss of a supportive service (e.g. - respite services, appropriate school placement) • Is the individual's current experience/symptoms similar to a past situation (i.e. - “history repeating itself”)? For example, they might have had a loss, separation etc. in the past |
Perpetuating (What chronic things are going on?) | • Do they have a chronic illness, functional impairment caused by cognitive deficits, or a learning disorder? • Lack of medication optimization (suboptimal doses) • Lack of treatment or follow up for mental illness • Current substance use? • Chronic medical problems, chronic pain, or disability? • How is patient responding to hospitalization? • What are the degree of the symptoms right now? | One or more perpetuating psychological processes: • Cognitive: chronic negative thoughts and reinforcing environment • Dialectical: help-seeking and help-rejecting, chronic emotional dysregulation and poor distress tolerance • Interpersonal: Chronic/unresolved dysfunctional relationships, interpersonal conflicts, or role transitions • Psychodynamic: recurring themes throughout one’s life, chronic primitive defenses • What are their beliefs about self/others/world? What ideas have they internalized? • Are there self-destructive coping mechanisms, or traumatic re-enactments? • Ongoing poor coping skills, limited or lack of insight? • Personality traits (e.g. - unable to maintain consistent interpersonal relationships in borderline personality disorder) • How is their attachment style playing out in this particular situation? | • Chronic marital/relationship discord, lack of empathy from family/friends, developmentally inappropriate expectations • Chronically dangerous or hostile neighbourhood, trans-generational problems of immigration, lack of culturally competent services • Ongoing transitions and stressors • Poor finances or working long hours • Isolation, unsafe environment |
Protective (What is protecting them and keeping them well?) | • Good overall health • Absence of family psychiatric history • What is their response to medications (good response/no response, did they achieve remission, are they optimized on current medications)? • Do they have above-average intelligence, easy temperament, resiliency, specific talents or abilities? • No substance use is a protective factor | • Do they have ability to be reflective or modulate their affect? • Do they have ability to mentalize (see other's perspectives)? • Do they have a positive sense of self, or adaptive coping mechanisms? • Psychologically-minded, reflective, and capacity to change thinking patterns? • Have they previously responded well to therapy? • Good coping skills, good insight? | • Positive relationships, supportive community, and/or extended family/friends? • Religious/spiritual beliefs • Good interpersonal supports • Financial/disability support • Has an outpatient healthcare team: GP, psychiatrist, social, or case worker? |
Biological | Psychological | Social | |
---|---|---|---|
Predisposing | • Family history of mental disorders and substance use • History of concussions • Fearful/anxious temperament at birth | Step 4 | Step 3 |
Precipitating | • Increase in alcohol use in the last 3 months | Step 5 | • Recently fired from job |
Perpetuating | • Current dose of sertraline is subtherapeutic • Ongoing alcohol use | Step 6 | • Ongoing discord in her romantic relationship • Ongoing financial difficulties |
Protective | • Medically healthy | Step 7 | • Good interpersonal support from her best friend who brought her to hospital • Has a psychiatrist that she sees every month |
Now that you've filled in the easy parts from the history, the hardest part is conceptualizing the predisposing social factors (Step 3), and all of the psychological factors (Steps 4, 5, 6, 7). This is where you'll need to be creative and also think more in-depth about your patient. Ideally, each step should flow logically and intuitively into the next based on your framework, as you'll see in our case of Jane Doe. Having a framework for understanding of different psychological treatments and psychological theories can be helpful in making your psychological formulation flow intuitively (e.g. - attachment theory, cognitive behavioural therapy, dialectical behavioural therapy, interpersonal therapy, psychodynamic therapy). However, this can be done intuitively even without an in-depth understanding of these frameworks (we don't need to be Freud to do this). The more cases you go through (and more of the sample formulations below) the more comfortable you will be with formulating!
Step | Factor | Description |
---|---|---|
Step 3 | Social (Predisposing) | Early parental divorce, unstable home life, history of trauma. History of invalidation and lack of acknowledgement by parents |
Step 4 | Psychological (Predisposing) | (Led to) fears of abandonment which developed early in childhood |
Step 5 | Psychological (Precipitating) | Re-experienced these feelings of abandonment after being fired from work |
Step 6 | Psychological (Perpetuating) | Lack of adaptive coping mechanisms resulted in using self-harm to cope and avoid further emotional dysregulation. Additionally, the lack of coping mechanisms leading to intense thoughts of suicide. |
Step 7 | Psychological (Protective) | Previously responded well to DBT, and has a history of being psychologically-minded and insightful. University educated. |
Biological | Psychological | Social | |
---|---|---|---|
Predisposing | • Family history of mental disorders and substance use • History of concussions • Fearful/anxious temperament at birth | • Fears of abandonment which developed early in childhood • History of invalidation and lack of acknowledgement by parents | • Early parental divorce, unstable home life, history of trauma |
Precipitating | • Increase in alcohol use in the last 3 months | • Re-experienced these feelings of invalidation and abandonment after being fired from work | • Recently fired from job |
Perpetuating | • Current dose of sertraline is subtherapeutic • Ongoing alcohol use | • Her lack of adaptive coping mechanisms resulted in using self-harm to cope • Additionally, the lack of coping mechanisms leading to intense thoughts of suicide | • Ongoing discord in her romantic relationship • Ongoing financial difficulties |
Protective | • Medically healthy | • Previously responded well to DBT • History of being psychologically-minded and insightful • University educated | • Good interpersonal support from her best friend who brought her to hospital. • Has a psychiatrist that she sees every month |
You've got your table all filled out now. Now what? How do you present all this information and data? Remember there is no “right” or “wrong” way to present your formulation. But the most important thing about formulation is that it should be intuitive and flow logically. Some different presentation styles are suggested here.
The “4 Ps” formulation table can be a very rigid and systematized way of presenting a formulation. At its most basic, you could present each box sequentially and describe each factor. Most learners will use this method as it is the most “simple.” It is usually presented as Predisposing → Precipitating → Perpetuating → Protective factors. As you get better and more expert at formulating, you may not need to use this rigid structured format, and instead, will be able to present a more intuitive and organic formulation of the patient instead (see other methods below).
The narrative formulation of the patient is a less rigid presentation structure where you may not choose to present everything in the 4 Ps table, and instead focus on the key factors that you think are relevant:
A much more advanced and nuanced presentation might be using a more comprehensive formulation that integrates the 4Ps formulation through multiple lenses (e.g. - Eriksonian developmental stages, psychodynamic defenses, and dialectical behavioural):
Yet another way to present a formulation is in chronological order, starting from birth until present time:
Having certain common phrases to use can be helpful to structure your presentation. Here are some examples:
A good formulation should be integrative, and let you understand how all of the patient's factors interact to lead to the current situation. This gives you a sense of their current level of functioning, prognosis, and guides your direction for treatment and management decisions.
A good biopsychosocial formulation allows you to come up with a comprehensive and holistic treatment plan for your patient. Here is an example of a set of treatment recommendations for Jane Doe:
For good measure, here is another sample formulation for someone with a diagnosis of schizophrenia. Note that in this example, since the precipitating cause for acute psychosis (also applies to manic episodes) is more “biological,” it may be harder to identify underlying psychological factors (but that's OK too – even the most “biological” psychiatric disorders can often be precipitated by psychosocial stressors). Again let's fill out the easiest parts of the table first:
Biological | Psychological | Social | |
---|---|---|---|
Predisposing | • Family history of psychosis and schizophrenia | ? (Step 4) | ? (Step 3) |
Precipitating | • History of cannabis use at early age | ? (Step 5) | • Social isolation and withdrawn from family members |
Perpetuating | • Discontinuation of antipsychotics • Ongoing cannabis use and smoking, reducing the effectiveness of medications, and also exacerbating risk of psychosis | ? (Step 6) | • Ongoing social isolation due to psychosis causing him to be fearful of others |
Protective | • Medically healthy • Previously responded to antipsychotic medications • No history of developmental delay or head injuries | ? (Step 7) | • Followed by an early intervention in psychosis team • Supported by girlfriend and several close friends • University educated |
Now here is one potential example of a predisposing social and psychological formulation of psychosis (again, there are no right or wrong ways to formulate, it depends on the patient you have in front of you!)
Step | Factor | Description |
---|---|---|
Step 3 | Social (Predisposing) | • History of immigration (increases risk for psychosis) • Absent father, abusive mother, unstable home life |
Step 4 | Psychological (Predisposing) | Long-standing feelings of isolation and insecurity since childhood |
Step 5 | Psychological (Precipitating) | Joined a gang, entering a stressful lifestyle, led to increased hyper-vigilance and paranoia in the past few months |
Step 6 | Psychological (Perpetuating) | • Ongoing delusions leading patient become suspicious of healthcare workers/family • Psychosis leading to poor insight, and inability to reality test. He is unable to understand that persecutory delusions are a function of his psychosis. |
Step 7 | Psychological (Protective) | • Previously responded well to CBT for psychosis • Psychologically-minded and insightful when well |
Here's what the completed table would look like with the psychological factors incorporated.
Biological | Psychological | Social | |
---|---|---|---|
Predisposing | • Family history of psychosis and schizophrenia | Long-standing feelings of isolation and insecurity since childhood | • History of immigration (increases risk for psychosis) • Absent father, abusive mother, unstable home life |
Precipitating | • History of cannabis use at early age | Joined a gang, entering a stressful lifestyle, led to increased hyper-vigilance and paranoia in the past few months | • Social isolation and withdrawn from family members |
Perpetuating | • Discontinuation of antipsychotics • Ongoing cannabis use and smoking, reducing the effectiveness of medications, and also exacerbating risk of psychosis | • Ongoing delusions leading patient become suspicious of healthcare workers/family • Psychosis leading to poor insight, and inability to reality test. He is unable to understand that persecutory delusions are function of his psychosis. | • Ongoing social isolation due to psychosis causing him to be fearful of others |
Protective | • Medically healthy • Previously responded to antipsychotic medications • No history of developmental delay or head injuries | • Previously responded well to CBT for psychosis • Psychologically-minded and insightful when well | • Followed by an early intervention in psychosis team • Supported by girlfriend and several close friends • University educated |
As you do more formulation, you will notice that patients tend to present in “templates,” that is, certain diagnoses tend to follow a certain common theme of predisposing, precipitating, and perpetuating factors. The more you formulate, it can be helpful to have a rough template of different formulations for different diagnoses (e.g. - depression, self-harm, mania/psychosis, anxiety, etc.) It will make your job of formulating much easier.
The following readings below are excellent resources to further develop your formulation skills: